spl: fit: pass real compatible flags to fpga_load()

Convert taken FPGA image "compatible" string to a binary compatible
flag and pass it to an FPGA driver.

Signed-off-by: Oleksandr Suvorov <oleksandr.suvorov@foundries.io>
Tested-by: Ricardo Salveti <ricardo@foundries.io>
Tested-by: Adrian Fiergolski <adrian.fiergolski@fastree3d.com>
Link: https://lore.kernel.org/r/20220722141614.297383-9-oleksandr.suvorov@foundries.io


Signed-off-by: Michal Simek <michal.simek@amd.com>